hey team. got referred here by a few friends who read the board to try to find some help for the problem im having right now. the truck is an 89 toyota pickup 22RE with over 400000km on it (still runs beautifully, for the most part). There are a few problems happening right now that might be interrelated, so who knows. here it goes:

Recently, the truck started to have some weird issues with some major engine clunking. Basically, it happens at any speed, any gear, any temperature. What happens is that when i give it some gas, the engine just clunks and the truck jerks, even at high speed on the highway. it will kind of happen in spurts - sometimes it will happen ever 30 seconds and sometimes it will go an hour before it happens again. also, the check engine light comes on sometimes when it happens...but not every time.

It also has some troubles that sound similar when it starts up warm. i have to give it a lot of gas and it shudders a lot before it gets going. Sounds kind of like it should sound when starting it up in cold weather.

the other problem is with temperature regulation. When i am sitting in traffic barely moving, the truck heats up significantly - almost overheating. as soon as i start driving again and getting some air flowing across the rad it cools right down to normal. This isnt really that big of a problem but it might have something to do with what i found out at the toyota dealership today.

I took it in to a dealership today to get it diagnosed. they told me that the check engine light gave a "code 22 - temperature sensor failure". When i picked it up the mechanic was gone and the guy I talked to didn't know much about the part. From what I searched so far on here I couldnt find anything about this.

So my question is, why would a water or coolant temp sensor cause the truck to do this? doesn't make sense to me and I don't really feel like replacing things that don't need to be replaced. Let me know what you think.

Thanks!

Had a similar problem a couple years back on my '87 Runner. Bad temp sensor had truck running very rich, I just disconnected sensor and truck began running better immediately.

hmm, interesting.

I think there are a couple of different temperature sensors, aren't there? one feeding the temp gauge and another for the EFI? I just had a similar problem on my other vehicle. the EFI's pretty simple on these vehicles, but a bad temp sensor can affect the A/F mixture and possibly cause the problems you're describing. my problem was just a wire that had slipped out of the plastic connector, so it basically wasn't connected to the sensor. I would have driveability issues until it warmed up. it wouldn't even idle on cooler days -- had to start it 3-5 times before it would stay on.

the bucking makes me think bad plug wire, though.

what year is your truck? some late 80's trucks had problems with the temp sensor/dash gauge, can't remember which. I installed an aftermarket gauge in mine, because my gauge would be all over the place and it would freak me out.

do you have any other symptoms of actual overheating? boilover or anything like that?

you might have two problems going on there, but if you're going by the gauge alone, it might be leading you in the wrong direction if the gauge itself is bad. if you're really getting overheating, you might have a failing cooling component causing your temperature climb -- bad thermostat, water pump or clogged radiator.

See if this describes your temperature issue:
- http://www.4crawler.com/4x4/CheapTricks/index.shtml#Thermostat

Hi Wilkez! Welcome to the board.

I know this might be a bit of a stretch, but when's the last time the timing chain was changed on the truck?

http://www.4x4wire.com/toyota/maintenance/timingchain/

The first time I had a timing chain fail, I'd have the truck stutter/stumble hard going down the road. The early warning sign is the ol' "rattle on startup"; are you experiencing this? The article above leads you to inspecting the timing chain guides; once they're broken, you'll have chain slap.

One of the other things that timing chain likes to do is eat thru the timing chain cover and compromise your water jacket. How's the coolant level look? Also, does your dipstick and/or oil cap look like a milkshake? If you've got coolant getting into the oil, it'll look like one.

Check that coolant level and keep an eye on it if nothing else seems out of place- at least for now. Probably wouldn't hurt to do a compression test. Low numbers in adjacent cylinders can point to a head gasket on its way out.

Just a couple things to check to keep any collateral damage to a minimum, as the 22Rxx's are an interference engine.

Hope that helps.

thanks for the help. The thermostat is new within the past 6 months I changed it out last spring.

No coolant problems and the timing chain was the first thing I mentioned to the guys at the dealership, but I'll check thru that guide anyways looks like good stuff to know.

The weird thing is now that its had the codes cleared, the problem has disappeared and hasn't reoccurred for almost 200km (it normally would have happened 20 times in that span). So I figure i'll just roll with it and see what happens for now.

Thanks!

If my 85 22re sputtered I would check the electrical system first, ignition etc. I would'nt think my temp sensor would affect it. The fuel pump in the tank maynot be strong enough to keep the pressure up. I can't remember if I found if a pump slowly goes bad or is bad when it quits all together.

In case anybody ever searches for this again, I have fixed the problem and found out why all the problems were caused!

I replaced the temp sensor with a new one from toyota, it cost about 80 bucks canadian (ouch!). Might have been possible to just clean the old one up, it was looking rough but basically just corroded and caked up, but I had already bought the new one when I took the old one out so now I have a spare I suppose...

I found some articles here on another site: here

The temp sensor feedbacks to the EFI stuff to control fuel/air mixture because of the efficiency of burning fuel at different temps. When the sensor fails, a/f ratio is out of whack and truck stalls and bogs. Temp problems also seem to be doing better, although the weather is well below freezing now so i'll have to wait till it warms up to tell for sure.

hope this helps somebody in the future

Just toss that old sensor, it's bad. Cleaning it up won't do a thing for the failed electronic sensor inside the shell you see.

Every sending unit that feeds into the ECU is important & can cause poor running. If I get a code, I first clean the wire contacts of the sender & try again. If that fails replace it, it's money well spent in most cases.

Dave